PURPOSE: To shorten the time required to find aimed data by storing the output of an A/D converter at successive sampling points in specific addresses of a data memory, and calculating a distance to a body on the basis of a storage contents.
CONSTITUTION: A pulse generator 1 is connected to an ultrasonic wave receiver 2 and a counter 3, and a reflected wave from the body 11 is inputted to the A/D converter 6 through an amplifier 4; when the signal of the amplifier 4 is larger than a reference signal 23, the comparator 5 inputs its output to an address memory 8 through a pulse generator 7 and the current output of the counter 3 is stored in the memory 8. Further, the output of the converter 6 which is sampled at the count period of the counter 3 is stored in the data memory 9, whose address is determined according to the output of the counter 3 at each sampling point and the contents of the memories 8 and 9 are processed by a processor 10 to calculate the distance to the body. Consequently, it is judged whether data to be stored is aimed data or not.
TSUBOI NOBUYOSHI
TAKENAGA HIROSHI
KANEZAKI MORIO
